Jenkins publish over ssh shows error "jenkins.plugins.publish_over.BapPublisherException: Failed to add SSH key."

Question

For connecting jenkins with remote server with ssh I installed publish over SSH plugin in jenkins. But after configuration it shows error as jenkins.plugins.publish_over.BapPublisherException: Failed to add SSH key. Message [invalid privatekey: [B@7934add]

Initially I logged as jenkins user in server as "sudo su jenkins" After this I typed "ssh-keygen" and give the passphrase value and given the path of key in jenkins configuration.

my passphrase is the value which I given while creating ssh-keygen

my passphrase/password is same value which I given while creating ssh-keygen. I don't am I correct with this point

But all my configuration when I click test configuration button it shows "

Failed to connect or change directory

jenkins.plugins.publish_over.BapPublisherException: Failed to add SSH key. Message [invalid privatekey: [B@3085b39b]"

Answer 1

The path to key should be the path to the private key id_rsa.

Not the public one id_rsa.pub (which is indeed an invalid... private key)

Creating an SSH key pair has generated:

• /var/lib/jenkins/.ssh/id_rsa (private key)
• /var/lib/jenkins/.ssh/id_rsa.pub (public key)

Use the old PEM format (not the new OpenSSH one)

ssh-keygen -t rsa -C "jenkins" -m PEM -P "" -f /var/lib/jenkins/.ssh/id_rsa

For an SSH session to be opened, the public key need to be copied over to the remote server, in /home/ubuntu/.ssh/authorized_keys.
If you have the remote ubuntu user password, you can use the ssh-copy-id command, as seen here:

ssh-copy-id -i /var/lib/jenkins/.ssh/id_rsa ubuntu@remoteserverip

Then you can test, as sudo su jenkins, the connection with ssh -Tv ubuntu@remoteserverip

Answer 2

It seems that MacOS uses a newer technology to generate the keys.

Generating the Key with -m PEM solved the issue for me.

The complete call was: ssh-keygen -t rsa -b 4096 -m PEM and then following the steps that Prakash said.

Source

Answer 3

You will need to create a public/private key as the Jenkins user on your Jenkins server, then copy the public key to the user you want to do the deployment with on your target server.

Step 1, generate public and private key on build server as user jenkins

build1:~ jenkins$ whoami
jenkins
build1:~ jenkins$ ssh-keygen
Generating public/private rsa key pair.
Enter file in which to save the key (/var/lib/jenkins/.ssh/id_rsa): 
Created directory '/var/lib/jenkins/.ssh'.
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in /var/lib/jenkins/.ssh/id_rsa.
Your public key has been saved in /var/lib/jenkins/.ssh/id_rsa.pub.
The key fingerprint is:
[...] 
The key's randomart image is:
[...]
build1:~ jenkins$ ls -l .ssh
total 2
-rw-------  1 jenkins  jenkins  1679 Feb 28 11:55 id_rsa
-rw-r--r--  1 jenkins  jenkins   411 Feb 28 11:55 id_rsa.pub 
build1:~ jenkins$ cat .ssh/id_rsa.pub
ssh-rsa AAAlskdjfalskdfjaslkdjf... jenkins@myserver.com

Step 2, paste the pub file contents onto the target server.

target:~ bob$ cd .ssh
target:~ bob$ vi authorized_keys (paste in the stuff which was output above.)
Make sure your .ssh dir has permissoins 700 and your authorized_keys file has permissions 644

Step 3, configure Jenkins

In the jenkins web control panel, nagivate to "Manage Jenkins" -> "Configure System" -> "Publish over SSH"
Either enter the path of the file e.g. "var/lib/jenkins/.ssh/id_rsa", or paste in the same content as on the target server.
Enter your passphrase, server and user details, and you are good to go!